The terminal nature of HIV infections has prompted demands for large quantities of HIV proteins for research related to understanding the virus and potentially developing therapeutic treatments for combatting the disease. Verax Corporation has developed a unique system for the mass culture of mammalian cells in a continuous fluidized bed system. The heart of the technology is the Microsphere, a collagen based micro-carrier that permits cell population densities in excess of 108 cells/ml. This system has already been successfully used for the large scale production of several protein therapeutics. The goal of this research is two-fold. First, we plan to investigate the use of Microspheres as a substrate for the growth and production of the HIV-1 gp-120 protein by a genetically engineered HeLa cell. The goal of this portion of the determine the efficacy of using this system for gp-120 production the characteristics of the matrix to permit maximum cell density and productivity. Second, we plan to develop a continuous culture micro-reactor for use with Microspheres. The development of such a system is essential to conducting this research because of the inadequacy of other small scale bioreactors for conducting research on microspheres. It may also permit inexpensive lab scale production of the gp-120 and other HIV proteins.